Lack of foods rich in folic acid to blame for birth defects rise
Published 19/03/2014 | 02:30
An unexpected rise in birth defects such as spina bifida may be linked to households cutting back on foods which naturally contain folic acid.
There has been a worrying increase in the rate of neural tube defects in babies born since 2009, reversing a trend from the previous decade.
Neural tube defects include spina bifida, which can cause paralysis of the lower limbs, and anencephaly. The latter results in the absence of parts of the brain which leads to death shortly after birth.
A woman who has an adequate intake of folic acid before and during pregnancy reduces her baby's risk.
The new study found 236 babies with a neural tube defect were born between 2009 and 2011 – prompting a call for the Government to make the fortification of bread with folic acid mandatory.
The increase is a reversal of trends earlier in the decade, the findings in the 'Journal of Public Health' showed.
The authors suggested the recession may have led households to reduce spending on foods which contain folate, the natural form of folic acid, such as green leafy vegetables.
"Our study suggested the rate (of increase of defects) may be lower in the Dublin region.
"It is possible that socio-economic differences on food expenditure in households may explain the disparity as Dublin households have up to 20pc more disposable income," they pointed out.
A neural tube defect occurs when the tube fails to close properly, leaving the developing brain and spinal cord exposed to amniotic fluid. But the B vitamin taken before and during pregnancy can reduce the risk.
The study, led by Robert McDonnell, a public health specialist in the HSE, looked at 225,998 births and identified 236 babies with a neural tube defect over three years.
This gave an incidence rate of 1.04 per 1,000 births, rising from 0.92 in 2009 to 1.17 in 2011. Nearly half (45pc) of the babies had anencephaly and 49pc had spina bifida, while 6pc were diagnosed with encephalocoele, which causes protrusion of the brain. One in five involved the termination of pregnancy abroad.
The authors found that among the women whose intake of folic acid in pregnancy was known, just 13.7pc had taken it before becoming pregnant.
Women who are trying to get pregnant are advised to take a 400 microgram folic acid tablet every day until they are 12 weeks' pregnant. Health authorities here adopted a policy of mandatory fortification of staple foodstuffs with folic acid in 2006 but it was postponed due to the fall in these defects.
Regionally, the incidence of the defects per 1,000 births was as follows: Dublin (0.76), mid-east (1.06), mid-west (1.09), southeast (1.25), southwest (0.95), border (1.34), midlands (1.46) and west (1.09).
The authors, who include Professor Michael Turner, obstetrician in the Coombe Hospital, said: "The rise in rates is in the indigenous Irish rather than among immigrant mothers.
"In Ireland, unlike most other countries in Europe, the vast majority of spina bifida cases are liveborn. We believe that the results of our national study provide grounds for an urgent review of public health policy on folic acid fortification, folic acid supplementation and pre-conceptional care in Ireland."